Pure Data Vanilla Patch No Audio

Using Zynthian
1

I’m running a headless zynthian instance (oral-2505.1) on an RPi 4 + HIBerry DAC+ with a connected Axiom 25 MIDI keyboard controller.

Instrument chains work fine. Preinstalled Pure Data synth chains work fine.

I wrote two pure data vanilla patches. One is a simple monophonic synth patch that plays tones based on mini note input, the other just plays a tone without anything midi input. Both patches run fine on OS X.

I installed PD patches on zynthian via webconf in the Pure Data sub directory, and rebooted pi. They appear to install fine but there is no sound for either. Each patch is named ‘main.pd’ in a folder then zipped and uploaded.

IMG_2441.HEIC
IMG_2441.HEIC3024×4032 2.75 MB

I’ve attached both patches if anyone wants to test on their build.

MonophonicSynthPatch.pd (480 Bytes)
ZynthianHybridPatch.pd (336 Bytes)

Any ideas what I’m doing wrong? It’s not a midi input issue and preinstalled PD patches work fine. Some sorting of routing issue?

I found this thread about Pure Data jack connection:

Could this be related to my issue? I’m not sure how to manually connect puredata jack client to zynmixer.

2

I was looking at the Pure Data docs:

https://wiki.zynthian.org/index.php/Pure_Data

Saw that I was missing the configuration yml file in zip. So I added this to patch zip.


main_file: "MonophonicSynthPatch.pd"

General:
 volume:
  midi_cc: 7
  value: 127
 decay time:
  midi_cc: 20
  value: 120
 release time:
  midi_cc: 21
  value: 5
 tine decay:
  midi_cc: 22
  value: 80

Now I see some touch widgets when I load patch, but still no audio.

3

I downloaded your files and zipped each. Then I uploaded them to my zynthian using webconf. They both produced sound. I test both in oram 2505.1 and also in vangelis. I noticed the sound was only present in the left channel, so I enabled vnc to inspect the patch. The output was only connected to the left inlet of [dac~] so I connected the right inlet as well and now have sound on left and right channels. Have you enabled vnc to inspect the patch and the connections in patchage to troubleshoot? The connections in Patchage should look something like this:

PD_Patch
PD_Patch1771×549 103 KB

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4

@ronsum Thanks for helping my troubleshoot my patches. I’m glad they work, just need to figure out why not on my setup.

I’ll fix the inlet issue on the dac in PD and look and VNC engines in the webconf app to see if the PureData connections match your screen shot.

Being completely new to zynthian and PD I wasn’t sure where to check connections.

5

Once you get sound working, you can edit and save the patch on the Zynthian using vnc. You can also look at other PD patches and their YAML files to see how to properly add the midi controls. Your YAML file wont do anything until you add the controls to the patch. In other words, since your YAML assigns midi cc 7 for volume control, you should add a working volume control in pd and attach a [ctlin 7] object to control it. Once that is done, you can use Zynthian’s midi learn feature to make it respond to your choice of encoder on your midi keyboard.

6

Thanks for the tips @ronsum about the YAML config. That will come in handy when my patch gets more fancy. In my testing I was downloading existing PD patches which I knew worked and pasted in my own patch code and uploaded the edit and still no audio. I suspect the issue is the connections like you showed in patchage not being connected. I will report back with my findings.

7

@ronsum Solved it! So when I open up VNC engines in webconf app the routing in patchage was fine. But I could see PD was throwing an error trying to load my patch. I had uploaded my patch into a folder called “My Patches”. I guess it didn’t like space character in the folder name, once removed the space the error disappeared and I can finally hear audio! Thanks for pointing me in the right direction!

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